A new species of Ariocarpus, A. bravoanus, is described. This species, which is known only from a single locality in San Luis Potosí, Mexico, has an array of morphological features reflecting an intermediate position between the two subgenera recognized within the genus: subgen. Roseocactus and subgen. Ariocarpus; however, A. agavoides appears to be its closest relative.

The history of the genus Vanheerdea, its circumscription and position, are described. The characters of the genus are analysed and two species are distinguished. The names of the genus and species are validated: Vanheerdea L. Bolus ex H.E.K. Hartmann, V. roodiae (N.E. Br.) L. Bolus ex H.E.K. Hartmann and V. primosii (L. Bolus) L. Bolus ex H.E.K. Hartmann.

Further taxonomic and nomenclatural notes are provided on various genera of Cactaceae. Proposals include the treatment of Pilocereus subg. Oblongicarpi (Croizat) Croizat (Subpilocereus Backeberg) and Mirabella Ritter as subgenera of Cereus and confirmation of the generic status of Pseudoacanthocereus Ritter. The application of various specific names is discussed along with miscellaneous questions of typification, orthography and citation.

The literature concerning tissue culture of cacti and other succulents is reviewed, with sections dealing with the major succulent families. The most work has been carried out on the Cactaceae and Crassulaceae, with fewer references to the Agavaceae, Aizoaceae, Aloaceae, Asclepiadaceae and Euphorbiaceae and other families. For each family, species which have been successfully propagated in vitro at Kew are listed.

The genus Monanthes Haworth (Crassulaceae) is critically revised. 10 species and 1 heterotypic subspecies are recognized and classified into 3 sections in this study: sect. Monanthoidea incl. M. atlantica, M. lowei, M. brachycaulos, M. minima, M. pallens, M. icterica; sect. Monanthes incl. M. polyphylla ssp. polyphylla, M. polyphylla ssp. amydros, M. muralis; sect. Sedoidea incl. M. laxiflora, M. anagensis. Keys are given for their identification, as well as descriptions for each taxon together with synonyms, distribution, a list of specimens examined and additional notes. Putative inter- and infrageneric relationships are discussed on the basis of comparative morphology.

The nomenclatural status of the two names Leucosedum Fourreau and Sedella Fourreau is examined and both are found to be invalid under the ICBN. In order to make the name available for a popular account, the new combination Bryophyllum gracilipes is published.

Seeds of Ariocarpus retusus Scheidw. were germinated under sterile conditions on solid Murashige and Skoog (MS) medium containing 20 g/1 sucrose and 20% (v/v) coconut water. The seedlings produced callus on the same medium, and after 3–4 months the first somatic embryo appeared. However, massive production of pale yellow somatic embryos started only after 14–16 months of culture. Calli were subcultured on to fresh medium every eight weeks. For subculture, the same medium was used but with only 15% (v./v) coconut water. For further growth, somatic embryos were placed on hormone-free MS medium or Schenk & Hildebrandt (SH) medium. The seedlings could then be grafted on Pereskiopsis velutina for further development.

Opuntia werneri, dedicated to Werner Uebelmann (Switzerland), is a striking new taxon from E Brazil, related to the widespread O. palmadora, from which it differs mainly in its fruits.

New synonymy is given for Caralluma adscendens which now includes the species C. subulata and C. dalzielii and is distributed from West Africa to peninsular India.